Modern endoscope devices are used in a wide range of applications. In medical fields, they are used to provide diagnosis and treatment in the body. In industrial fields, they are used to inspect and repair machines and the interior of pipes. Endoscope devices are also used for rescue purposes during disasters; they are used in the search for victims trapped within collapsed buildings.
A typical endoscope device has a control unit and a probe unit arranged at the distal end of a wire that extends from the control unit (See Patent Document 1). The control unit includes a pair of operation knobs for bending the distal end of the probe unit vertically and horizontally. One operation knob can be rotated to pull one of the wires connected to that knob to bend the distal end of the probe unit vertically. Similarly, the other operation knob can be rotated to pull the other wire connected to that knob to bend the distal end of the probe unit horizontally. Thus, an operator can inspect a space in a vertical or horizontal direction by rotating the pair of operation knobs. To inspect the intermediate ranges between the vertical and horizontal directions, the operator will rotate the control unit itself to rotate the probe unit within the same plane. The wire is inserted within a flexible tube along with a camera cable for imaging. The distal end of the flexible tube, along with the wire, is connected to the probe unit while the proximal end of the flexible tube, along with the wire, is connected to the control unit. This construction enables the operator to cover almost 360° of the space by rotating the operation knobs of the control unit to bend, the probe unit and by rotating the control unit itself to rotate the probe unit, along with the flexible tube, within the same plane.
In conventional endoscope devices, however, the vertical and the horizontal bending movements of the distal probe unit are independently controlled by the individual operation knobs, so that when the operator attempts to, for example, redirect the vertically bent distal probe unit in the horizontal direction, the distal probe unit must first be brought back into the straight position before it is bent in the horizontal direction. This is a complex and time-consuming procedure.
In addition, when inspecting the intermediate ranges between the vertical and the horizontal directions of the probe unit in a conventional endoscope device, the operator must rotate both the control unit and the flexible tube to ensure that the probe unit rotates within the same plane. This forces the operator to hold the control unit and the flexible tube in both hands. Furthermore, the accuracy of inspection may vary significantly depending on the skill of the operator, making it difficult to maintain consistent inspection results.    Patent Document 1 Japanese Patent Application Laid-Open No. 2002-125918